尿素氧化反应(UOR)是一种很有前途的可再生能源生产技术,为电解水制氢提供了有效的替代方案,因此开发高效稳定的UOR催化剂至关重要。本文通过NaBH4还原和硒化策略合成了富含Co、Mn和Mo的硒化镍催化剂(NiCoMnMoSe),该催化剂具有球形纳米...尿素氧化反应(UOR)是一种很有前途的可再生能源生产技术,为电解水制氢提供了有效的替代方案,因此开发高效稳定的UOR催化剂至关重要。本文通过NaBH4还原和硒化策略合成了富含Co、Mn和Mo的硒化镍催化剂(NiCoMnMoSe),该催化剂具有球形纳米颗粒与纳米片共存结构。X射线光电子能谱(XPS)、紫外-可见分光光度法(UV-vis)和原位bode相图表明,Mn和Mo的协同效应调节了Ni/Co的电子结构,提高了硒化物的电导率并加速加速电荷转移动力学,从而促进Ni^(2+)/Co^(2+)快速转变为活性Ni^(3+)/Co^(3+),并显著降低了NiCoMnMo-Se的起始电位。在UOR过程中,大部分Mo和Se被氧化成钼酸盐和硒酸盐溶解在电解质中,暴露出更多的Ni(Co)OOH活性位点,从而加快UOR反应。另外,Mn的引入稳固了活性位点,极大地增强催化剂的整体稳定性。正如预期的那样,NiCoMnMo-Se催化剂在UOR过程中表现出优异的电催化和稳定性性能,在仅1.38 V vs.RHE(相对于可逆氢电极)的电位下实现了50 mA·cm^(−2)的电流密度,并在50 mA·cm^(−2)电流密度下运行50 h后电压仅上升3.0%。当NiCoMnMo-Se和商业Pt/C组装成用于碱性尿素电解的双电极体系时,它只需要1.59 V vs.RHE便达到50 mA·cm^(−2)。展开更多
The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that ...The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that can be transformed into porous carbon.We prepared an ac-tivated carbon by microwave pyrolysis combined with KOH activator using the CTLS as starting materials.The carbon had a specific surface area of 556 m^(2)g^(-1) and a honeycomb-like structure.Two kinds of N-doped activated carbons were then synthesized by thermal decomposition of the activated carbon,either combined with urea,or impregnated with eth-anolamine.Both N-doped activated carbons have an in-creased number of nitrogen and amine surface groups.However,only the urea treatment was effective in improv-ing the initial capacity of the cell(1363 mAh g^(-1)),which is probably linked to the sorption of long-chain polysulfides.This investigation confirms that it is possible to use the thermal de-composition of urea to obtain carbon materials from CTLS for use as the sulfur-host cathode in Li-S batteries and improve their performance.A radial basis function neural network was fitted to provide statistical support for the experimental results,which confirmed the importance of the nitrogen content of the carbons in determining the discharge capacity of the cells.展开更多
文摘尿素氧化反应(UOR)是一种很有前途的可再生能源生产技术,为电解水制氢提供了有效的替代方案,因此开发高效稳定的UOR催化剂至关重要。本文通过NaBH4还原和硒化策略合成了富含Co、Mn和Mo的硒化镍催化剂(NiCoMnMoSe),该催化剂具有球形纳米颗粒与纳米片共存结构。X射线光电子能谱(XPS)、紫外-可见分光光度法(UV-vis)和原位bode相图表明,Mn和Mo的协同效应调节了Ni/Co的电子结构,提高了硒化物的电导率并加速加速电荷转移动力学,从而促进Ni^(2+)/Co^(2+)快速转变为活性Ni^(3+)/Co^(3+),并显著降低了NiCoMnMo-Se的起始电位。在UOR过程中,大部分Mo和Se被氧化成钼酸盐和硒酸盐溶解在电解质中,暴露出更多的Ni(Co)OOH活性位点,从而加快UOR反应。另外,Mn的引入稳固了活性位点,极大地增强催化剂的整体稳定性。正如预期的那样,NiCoMnMo-Se催化剂在UOR过程中表现出优异的电催化和稳定性性能,在仅1.38 V vs.RHE(相对于可逆氢电极)的电位下实现了50 mA·cm^(−2)的电流密度,并在50 mA·cm^(−2)电流密度下运行50 h后电压仅上升3.0%。当NiCoMnMo-Se和商业Pt/C组装成用于碱性尿素电解的双电极体系时,它只需要1.59 V vs.RHE便达到50 mA·cm^(−2)。
文摘The use of carbon from waste biomass has the potential to eliminate the drawbacks of Li-S batteries and improve their overall performance.Chrome-tanned-leather-shavings(CTLS)are a readily available waste product that can be transformed into porous carbon.We prepared an ac-tivated carbon by microwave pyrolysis combined with KOH activator using the CTLS as starting materials.The carbon had a specific surface area of 556 m^(2)g^(-1) and a honeycomb-like structure.Two kinds of N-doped activated carbons were then synthesized by thermal decomposition of the activated carbon,either combined with urea,or impregnated with eth-anolamine.Both N-doped activated carbons have an in-creased number of nitrogen and amine surface groups.However,only the urea treatment was effective in improv-ing the initial capacity of the cell(1363 mAh g^(-1)),which is probably linked to the sorption of long-chain polysulfides.This investigation confirms that it is possible to use the thermal de-composition of urea to obtain carbon materials from CTLS for use as the sulfur-host cathode in Li-S batteries and improve their performance.A radial basis function neural network was fitted to provide statistical support for the experimental results,which confirmed the importance of the nitrogen content of the carbons in determining the discharge capacity of the cells.
